Excluding the volatile food and energy categories, core prices rose 0.3 percent in January, pushed up by higher costs for apparel, air fares and rents. Core prices have risen 1.9 percent in the past year, below the Fed’s inflation target.

The Fed is purchasing $85 billion in Treasurys and mortgage bonds each month in an effort to keep interest rates low. Last month, some Fed policymakers expressed concern the purchases could cause inflation.

Low inflation leaves consumers with more money to spend, which benefits the economy.

Inflation slowed dramatically last year. Consumer prices rose only 1.7 percent in 2012, down from 3 percent in 2011.

The relief at the pump ended in recent weeks, with prices rising steadily this month. Higher gas prices will likely push up measures of inflation in February, though economists expect overall price increases to stay mild.

Gas prices averaged $3.77 a gallon nationwide on Wednesday, according to AAA. That’s up 46 cents from just a month ago.

Tame inflation also makes it easier for the Fed to continue its efforts to accelerate the economy. If the Fed feared that prices were rising too fast, it might have to raise interest rates. The Fed has kept the benchmark interest rate it controls at nearly zero, a record low, for more than four years.

With job gains and economic growth steady but modest, many businesses are reluctant to raise prices for fear of losing customers. That’s helped keep inflation mild. Workers also aren’t able to demand higher wages when growth is weak. That limits their ability to spend more.

Still, several Fed policymakers suggested last month that the central bank might have to scale back its bond buying to avoid escalating inflation or disrupting bond markets, according to minutes of the Fed’s Jan. 29-30 meeting released Wednesday.